Implemented in 2.0?

Any further info on this?

I talked with George Lebl about this issue, and he responded as follows:

This is sort of a blue sky feature bug, but it may be totally bogus.  The
full locale stuff should really be user specific and set in some control
center setup dialog thingie.  It should really not have much to do with gdm I
don't think (nowdays).  My current opinion is that the language selection in
gdm is just so that the user can log into their first session in their own
language, but further refinements to the locale should really be set by
gnome-session when the user actually logs in.  I think you should talk to the
i18n people and there could be some ui review on how this should work and
interact together.

FWIW, I agree fully with comment 3. GDM should not be a locale tweaker, it's
there for logging in.
In my opinion the current language/locale selection feature is primarily there
to allow the user to be able to at least use the desktop, since a wrong
language/locale used may in some case be a showstopper even for basic use of the
desktop. Hence, language selection is essential. I doubt that can be said about
many other locale settings -- if the values are wrong it might be irritating,
but most of the time they're not essential to basic use of the desktop and won't
be showstoppers. They can be modified later on (at least it should be possible
to do that). They don't belong in GDM.

Yes, this is something we want Carlos' "Language and Culture" capplet (or
something equivalent; note that this would include patching many core desktop
components, such as gnome-session, gnome-panel, etc. to support it) to provide,
not GDM.

I agree with Christian and Danilo very much. I believe this bug should be
resolved as NOTABUG.

Closing as NOTABUG as suggested.